Compressor



Dec. 11, 1951 J NAAB 2,578,199

COMPRESSOR Filed Jan. 22, 1948 INVENTOR 38 JULIUS NAAB Hi 8 ATTORNEY.

Patented Dec. 11, 1951 COMPRESSOR Julius Naab, Easton, Pa., assignor to Ingersoll- Rand Company, New York, N. Y., a corporation of New Jersey Application January 22, 1948, Serial N 0. 3,749

2 Claims. 1

This invention relates to compressors, and more particularly to a spraying system for cooling the compressed air discharged from a compressor.

It is common knowledge that oil used for lubricating compressors of the type to which this invention relates, will collect in the discharge line and, under certain conditions, become ignited by a piece of incandescent carbon or other foreign material in the discharge air stream which results in considerable damage to the line and associated equipment. In order to reduce the pos sibility of such fires, it is the present practice to provide intercoolers and aftercoolers which lower the temperature of the discharge air. However, this practice is not entirely satisfactory in that fires have occurred in the line between the compressor and the cooler and in some instances in the cooler itself.

An alternative and more satisfactory method for preventing these fires is to introduce a fine spray of water directly into the discharge line at a point adjacent to the compressor. Heretofore, this alternative presented a problem in that a pressure sufificient to force or eject the water into the line was not in all cases available.

It is accordingly one object of my invention to spray cooling water into the discharge line of a compressor by means of the pressure developed within said compressor.

A second object is to introduce water into the discharge line of a compressor only during the time the compressor is delivering air.

Another object is to introduce water into the discharge line of a compressor in quantities which vary directly with the output of the compressor.

Still another object is to pump water into the discharge line of a compressor using the compression in the ends of said compressor to operate the pump in timed relation with the operation of the compressor discharge valve.

Further objects will be in' part obvious and in part pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference numerals refer to similar parts,

Figure 1 is a longitudinal view of a compressor embodying the present invention,

Figure 2 is a view in elevation, partly in section, of a portion of a compressor and discharge conduit showing the invention applied thereto, and

Figure 3 is a vertical elevation, in section, of a detail.

Referring to the drawings, l designates in general a variable capacity compressor having inlet and discharge conduits H and I2 and on which is mounted a clearance control device 13, described in detail in the Metzgar Patent No. 2,125,355, issued August 2, 1938, and adapted to the lower portion of the cylinder housing It thereof are fluid pumps l5 which serve as means for delivering water, under pressure, to a conventional type spray nozzle l6 located in the discharge conduit l2 at a point below, as viewed in Figure 2, the compressor discharge valves 46. The nozzle I6 is also positioned so that the di rection of flow of water sprayed therefrom is counter to the flow of air, or other gas, passing through the discharge conduit [2.

In the form of the invention illustrated, each of the pumps [5 include an elongated housing I? having a longitudinally disposed chamber iii of general cylindrical form to receive a reciprocatory piston i9. As shown, the upper portion 2:! of the chamber I8 is of greater diameter than the lower portion 2| to receive the enlarged end or head 22 of the piston [9, whereas the lower part of the'piston l9 extends into the smaller chamber portion 2|. An atmospheric port 23 in the housing I! communicates with the chamber portion 20 to permit the immediate detection of any leakage of pressure fluid along the piston 19 and also serves as a drain for the chamber l3.

Seated on the upper end of the housing I? is a cover plate 24 which encloses the upper end of the chamber I8 and has an opening 25 therethrough adapted to receive one end of a pipe 26. The other end of the pipe 26 is threaded in an indicator hole 21, at the end portion of the cylinder housing M, which is normally present in a reciprocatory compressor for use in obtaining pressure-volume diagrams. The compressor l9 herein illustrated is of the double acting type and, therefore, an indicator hole and pump are located at each end of the housing l4 so that an auxiliary pressure which exceeds the compressor discharge pressure is available whenever the compressor is delivering air. That is, with the aforedescribed arrangement the pressure surface of the piston head 22. is constantly exposed to pressure fluid delivered directly from the compressor through the pipe 26 and the piston I9 is actuated downwardly on its working stroke to force water into the discharge conduit whenever the pressure within the end of the cylinder housing M, to which it is exposed, reaches a predetermined value. The piston I9 is returned on its upward or non-working stroke by a spring 28 which encircles the piston l9 and abuts the shoulder 29 on the head 22 and the surface 30 defining the lower end of the chamber portion 20.

In the lower part of each of the housings I 'I are cooling water inlet and outlet conduits 3I and 32 that communicate with the smaller end of the chamber portion 2I. Threaded in each of the inlet conduits is a branch of a supply pipe 33 for conveying cooling water to the pumps I from a source (not shown) and a pipe 34 having a branch threaded in the outlet conduits 32 serves to convey water from the pumps I5 to the spray nozzle I6. Adapted within the inlet and outlet conduits are valves 35 and 36, respectively, which are of the poppet type and are normally held in the closed position by springs 3'! and 38, respectively.

The valves 35 and 36 are designed to open in response to predetermined fluid pressures within the smaller end of the chamber I8 and in this instance the valve 35 will remain closed during the working stroke of the piston and will open during the non-working stroke of the piston I9. In this manner cooling water is admitted into the chamber portion 2| wherein the pressure of the water is increased by the action of the piston i9 on its working stroke to a. value which may, due to the difference in area on the opposite ends of the piston I9, exceed the actuating pressure.

The amount the water pressure exceeds the compressor discharge pressure is, of course, dependent on the pressure required to operate the valve. 36 against the pressure of the spring 38 and the back pressure of the water in the pipe 34. Thus the valve 3% remains closed during the nonworking stroke of the piston to prevent the. flow of water into the chamber portion 2I from the pipe 34 and opens during the working stroke thereof to permit cooling water, under pressure, to be pumped to the nozzle I6 and thence it is. sprayed into the discharge conduit in such a manner as to obtain the most effective cooling of the air therein. A 'valve 39, in this instance of the needle type, is adapted in the pipe 34 tocontrol the rate of flow of water therethrough.

It is now readily apparent to those skilled in the art that the present invention provides asimple and inexpensive means for cooling the discharge air of a compressor, and by designing the piston I9 so that it begins its working stroke when the pressure surface on the head 22 is exposed to the compressor discharge pressure, the pumps I5 can be made to discharge water only during the time that the compressor is delivering air to the discharge conduit I2. Also, a timed relation between the pump I5 and the compressor discharge valve 40 at the same end of the cylinder housing I4 as the pump, may be maintained by controlling the fiow of water from the pump, with the valve 39, so that the piston I9 completes its working stroke at substantially the same time the associated discharge valve closes, thereby causing the volume of water delivered to the nozzle IE to be directly proportional to the volume output of the compressor. This is, of course, of importance in that under all conditions of output only the desired quantity of water will be ejected into the discharge conduit to cool the compressed air therein.

While I have shown and described one form of my invention, it is to be understood that various changes and modifications may be made therein without departing from the spirit of the invention as set forth'in the appended claims.

I claim:

1. In combination with a gas compressor having a discharge valve and discharge conduit, a nozzle located in the discharge conduit at a level below that of the discharge valve and positioned to direct a spray of cooling medium into said conduit in a direction counter to the flow of gas therethrough, and means adapted to said compressor and actuated by pressure fluid delivered therefrom for delivering to the nozzle a volume of cooling medium directly proportional to the volume output of said compressor.

2. In combination with a compressor having a cylinder, inlet and discharge conduits therefor, discharge valves at the opposite ends of said cylinder, a spraying system for cooling the air discharged from the cylinder comprising a nozzle adapted to said discharge conduit at a point below said valves, and pumps at the opposite ends of the cylinder actuated by pressure fluid delivered directly from said cylinder to pump cooling water to the nozzle in proportion to the discharge volume of the compressor.

JULIUS NAAB.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 117,626 Haskins Aug. 1, 1871 1,870,219 Aikman Aug. 9, 1932 2,125,355 Metzgar Aug. 2, 1938 2,404,660 Rouleau July 23, 1946 

